Citrus fruit, such as oranges, for example, is commonly harvested from citrus groves using manual picking and collection techniques. Of course, more automated approaches have also been developed in an attempt to lower harvesting costs. For example, U.S. Pat. Nos. 5,469,695 and 5,513,484; and published international patent applications WO02/089556 and WO02/069693, to Zehavi et al., disclose a harvesting system based upon so-called shake and catch technology. A shaker vehicle carries a shaker head to engage and vibrate a tree trunk to dislodge the fruit therefrom. The shaker head is carried by an extensible boom which can retract and extend the shaker head. In the extended position, the jaws of the shaker head engage the tree trunk and a hydraulically driven vibrator shakes the tree trunk. The shaker head can be retracted by the extensible boom for advancing to the next tree.
A fruit deflector is carried by the shaker vehicle and collects a portion of the fruit. A fruit collector vehicle is positioned along an opposite side of the tree. The fruit collector typically includes one or more fruit conveyors to catch the portion of the fruit falling thereon, as well as to receive fruit from the fruit deflector of the shaker vehicle.
The collected fruit is conveyed by the fruit collector vehicle to be temporarily held in a fruit trailer typically towed behind the fruit collector vehicle. The shaker vehicle and fruit collector vehicle are each advanced to a next tree for harvesting. Once filled, the fruit trailer is movable to a raised height and a door opened to thereby empty its contents into a fruit removal vehicle. The fruit removal vehicle is intermittently brought adjacent the fruit trailer to receive the fruit therefrom and transport the fruit to a collection area.
Of significant interest in the automated harvesting technology are efficiency of fruit collection, speed of collection, and, of course, cost and reliability of the various pieces of harvesting and collection equipment. Efficiency of fruit collection relates not only to the percentage of fruit shaken from the tree and collected, but also to how much fruit may be lost by damage in subsequent handling. The speed of collection may be hampered if the fruit is not quickly and safely urged toward the lower end of the fruit deflector where it then falls onto the fruit collector.
A typical fruit deflector, such as that disclosed in the above mentioned patents to Zehavi et al., is a static structure that relies on its incline and the pull of gravity to urge the fruit toward its lower end. It should also be noted that leaves, twigs, etc. are also shaken from the tree and these may present an impediment to the downward roll of the fruit from the fruit collector to the fruit collector. Accordingly, these drawbacks of the fruit deflector may result in lower fruit collection efficiency, and/or increased collection time thereby increasing harvesting costs.
It also typically important for efficient harvesting that the shaker head be quickly and accurately positioned into engagement with each tree trunk in the grove. The shaker head may be typically carried by an extensible boom which, in turn, is carried by the vehicle. Unfortunately, the shaker is typically relatively heavy, but it should also be positioned accurately and carefully by the boom to avoid damage to the tree trunk. In addition, the shaker head should be quickly engaged and disengaged from the tree trunk for time efficient harvesting of course, the boom itself may be subject to damage by the substantial shaking forces imparted thereto.